This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 11-162563, filed Jun. 9, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a developing method and a developing apparatus for performing developing processing after exposure to a substrate such as a semiconductor wafer and the like.
In a resist coating and developing processing system for a process of photolithography in the fabricating processes of a semiconductor unit, resist coating processing is performed for forming a resist film on the surface of a semiconductor wafer. Developing processing is performed for developing the wafer after the exposure has been performed for the resist-coated wafer. These resist coating processing and developing processing are respectively performed by a resist coating unit and a developing unit which are included in the above system.
The developing unit comprises a spin chuck for rotating a semiconductor wafer firmly attached on the chuck with vacuum suction and a developing solution supply nozzle for supplying a developing solution onto the semiconductor wafer on the spin chuck. A developing solution supply nozzle used in a conventional developing unit comprises a nozzle body of a hollow rectangular rod shape. The nozzle body has a length longer than the diameter of the semiconductor wafer and a number of developing solution discharge ports formed to be aligned on the bottom surface of the body. In supplying the developing solution onto a semiconductor wafer using such a developing solution supply nozzle, the developing solution supply nozzle is moved to a position to be aligned over the semiconductor wafer diameter of the semiconductor wafer held on the spin chuck. Then, the semiconductor wafer is rotated at least 180xc2x0 while the developing solution is supplied to the internal space of the developing solution supply nozzle with a predetermined pressure to discharge it onto the semiconductor wafer from the discharge ports. Thereby, a uniform puddle of the developing solution is formed on the entire surface of the semiconductor wafer.
However, when the developing solution is applied as described above, the rotation speed is different between at the central portion of the semiconductor wafer and at the peripheral portion thereof. Since the rotation speed of the central portion is lower than that of the peripheral portion, the supply amount of developing solution at the central is larger than that at the peripheral portion. As a result, the developing processing does not proceed uniformly at the central portion and the peripheral portion on the wafer, whereby the line width of the circuit pattern is susceptible to deteriorating in uniformity.
In order to eliminate such a difference in the amount of the developing solution discharged at the central portion and the peripheral portion of a semiconductor wafer, a scan method in which the developing solution supply nozzle discharges the developing solution while scanning above the semiconductor wafer to thereby apply the developing solution on the semiconductor wafer has been employed more widely. However, in this scan method, since the developing processing does not always proceed uniformly between at the beginning and at the end of the scan, adequate uniformity in the line width of the circuit pattern is not obtained. Moreover, when the developing solution is discharged by such a scan method, the developing solution is supplied outside of the semiconductor wafer as well since the semiconductor wafer is formed in a disc shape, resulting in waste of the developing solution.
It is an object of the present invention to provide a developing method and a developing apparatus to reduce the variation in the developing processing and increase the uniformity of the line width.
It is another object of the invention to provide a developing method and a developing apparatus to reduce the amount of the developing solution unnecessary consumed.
According to the first aspect of this invention, there is provided a developing method for performing a developing processing comprising the steps of moving a developing solution supply nozzle relative to a substrate to scan the substrate with developing solution discharged from the developing solution supply nozzle in a band shape on the substrate after the exposure, and scanning the substrate two or more times with the developing solution from the above developing solution supply nozzle.
According to the second aspect of this invention, there is provided a developing apparatus for performing a developing processing by applying developing solution onto the substrate after the exposure, the apparatus comprising a developing solution supply nozzle configured to discharge the developing solution in a band shape on the substrate, a developing solution supply mechanism configured to provide the developing solution to the developing solution supply nozzle, a motion mechanism configured to move the developing solution supply nozzle relative to the substrate for scanning the substrate with the developing solution discharged from the nozzle, and a control mechanism configured to control the developing solution supply from the developing solution supply mechanism to the developing solution supply nozzle and the relative movement between the nozzle and the substrate so that the developing solution supply nozzle scans the substrate two or more times.
In the first and the second aspects of this invention, since the developing solution supply nozzle scans the substrate two or more times with the developing solution, the paddle formed on the substrate in a first scanning is agitated by the developing solution discharged from the nozzle in a second scanning to allow a uniform developing processing and improve the homogeneity of the line width.
Also, according to the third aspect of this invention, there is provided a developing method for performing a developing processing by applying developing solution onto the substrate subjected to an exposure, the method comprising the steps of forming a plurality of developing solution storage compartments in the developing solution supply nozzle, and applying the developing solution onto the substrate by discharging the solution from the developing solution supply nozzle onto the substrate while controlling the amount of the developing solution discharged from the storage compartments.
According to the fourth aspect of this invention, there is provided a developing apparatus for performing a developing processing by applying developing solution onto a substrate subjected to an exposure, the developing apparatus comprising a developing solution supply nozzle having a number of internal developing solution storage compartments which discharge the developing solution, a motion mechanism configured to create a relative movement between the developing solution supply nozzle and the substrate, a developing solution supply mechanism configured to provide the developing solution to each of the developing solution storage compartments of the developing solution supply nozzle, and a control mechanism configured to control the developing solution supply from the developing solution supply mechanism to the developing solution storage compartments so that a predetermined amount of the developing solution is discharged from each of the developing solution storage compartments of the above developing solution supply nozzle. The developing apparatus supplies the developing solution from the above developing solution supply nozzle to the substrate while creating a relative movement between the above developing solution supply nozzle and the substrate.
In the third and fourth aspects of this invention, the amount of unnecessary consumed developing solution can be decreased since the developing solution supply nozzle is internally divided into a number of developing solution storage compartments and the amount of the developing solution discharged from each compartment is controlled separately when applying the developing solution onto the substrate to decrease or stop the discharge of the developing solution above the area outside of the wafer.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.